Rotary impact crusher



July 15, 1969 e. T. GILBERT ROTARY IMPACT CRUSHER 3 Sheets-Sheet 1 Filed Feb. 4, 1966 FIG. 1.

INVENTOR w u G T E m E a y 1969 cs. T. GILBERT 3,455,517

ROTARY IMPACT CRUSHER Filed Feb. 4, 1966 5 Sheets-Sheet 2 FIG. 2 7

July 15, 1969 (a. T. GILBERT 3,455,517

ROTARY IMPACT CRUSHER Filed Feb. 4, 1966 3 Sheets-Sheet 5 United States Patent ice 3,455,517 ROTARY IMPACT CRUSHER George T. Gilbert, Bayport, Minn., assignor to Portec, Inc., Chicago, 11]., a corporation of Delaware Filed Feb. 4, 1966, Ser. No. 525,091 Int. Cl. B02c 13/00 US. Cl. 241189 9 Claims ABSTRACT OF THE DISCLOSURE A rotary impact crusher which has a plurality of hammers removably attached to a rotor by means of bolts and includes adjustable wedge means which retain the hammers on the rotors in case the bolts break when the crusher is operating. A pivoted housing is provided at one end of the casing to permit ready access to breaker bars for removal and replacement and means is provided to permit one of the breaker bars to be adjustable relative to its spacing from the hammer circle and also be yieldable when excessive pressure is applied to it.

This invention relates generally to crushing apparatus and more particularly to a crusher of the rotary impact type.

In apparatus according to the present invention, hard yet brittle material such as ore and quarry rock is reduced or disintegrated by impact with itself and against impact members comprising, first, a plurality of relatively fixed breaker bars mounted within a housing and secondly, a plurality of rigid impact hammer members disposed within the periphery of a rotor.

It is generally recognized that an impact crusher is one of the most eflicient means for breaking large pieces of rock-like substances into smaller fragments. However, there are many objections to be found in the construction of some of the prior known devices which greatly reduce the efiiciency of such apparatus. One of these disadvantages is the manner of attaching the rigid impact hammer members to the rotor. Various efforts have been made to provide for secure attachment of the hammers to the periphery of the rotor to insure positive retention of these hammers even after extended periods of operation wherein it will be understood that considerable forces are brought to bear upon the hammers and rotors due-to the resultant centrifugal action as well as the tremendous impact between the crushing material and hammers. Many of the prior known devices are very costly to produce in view of the extensive machining required to provide the specially constructed rotor face and-in addition quite often such a complexity of additional components are required in order to attach and secure the hammer upon the rotor that the entire operation involving these hammers has resulted in excessive down-time of the crusher for periodic maintenance thereof. Another drawback to be found in many of the prior known devices is the difficult and laborious servicing of the fixed impact or breaker members disposed within the housing of the crusher. It will be appreciated that these breaker bars are extremely heavy, far too large to be manually manipulated, and usually extend the entire width of the machine, being suitably journaled or otherwise attached at their ends to the opposite sidewalls of the housing. These breaker bars must be replaced not only when it is determined that they have become worn due to impact by the crushing material, but also when it is desired to alter the spacing between adjacent breaker bars in order to control the resultant size of the end product as delivered into the discharge area of the apparatus.

In crushers of the present type, the final impact zone is usually disposed in the area between the lowermost 3,455,517. Patented July 15, 1969 fixed breaker bar disposed most closely to the periphery of the rotor. It is well known to adjustably support this lowermost breaker bar so that the size of the final crusher product passing through this zone of the crusher may be regulated. However, it is also desirable that this particular breaker bar be yieldably mounted so as to be radially displaceable with respect to the rotor should a hard foreign substance such as tramp metal be wedged between the breaker bar and rotating hammers, in order to prevent jamming of the rotor or damage to the bearings supporting the rotor shaft.

Accordingly, one of the primary objects of the present invention is to provide a rotary impact crusher including improved means for removably attaching hammer members to the rotor.

Another object of the invention is to provide a rotary impact crusher having a plurality of impact hammer members removably attached to the rotor by means of a plurality of bolts and including adjustable wedge means insuring retention of said hammers within said rotor even upon the breaking of said bolts.

A further object of the present invention is to provide a rotary impact crusher having improved breaker bar mounting means facilitating the removal and replacement of the breaker bars as well as the adjustment of. the space therebetween.

Still another object of the present invention is to provide a rotary impact crusher having an adjustably mounted breaker bar provided with improved means to permit yielding of said breaker bar upon the application of excessive force thereto.

With these and other objects in view which will more readily appear as the nature of the invention is better understood, the invention consists in the novel construction, combination and arrangement of parts, hereinafter more fully described, illustrated, and claimed.

A preferred and practical embodiment of the invention is shown in the accompanying drawings, in which:

FIGURE 1 is a vertical sectional view of a rotary im pact crusher according to the present invention and illustrates in broken lines the alternate positioning of the movably mounted curtain of horizontal breaker bars.

FIGURE 2 is a transverse sectional view, partly broken away, and illustrates the attaching means for joining the hammer to the rotor.

FIGURE 3 is a partial side elevation of the structure illustrated in FIG. 2.

FIGURE 4 is a perspective view of the wedge block forming a portion of the retention means for mounting the hammers within the rotor.

FIGURE 5 is a perspective view of the hammer according to the present invention.

FIGURE 6 is a top plan view of one of the supporting means for the adjustable and yieldably mounted breaker bar.

FIGURE 7 is a side elevation of the structure shown in FIG. 6.

Similar reference characters designate corresponding parts throughout the several figures of the drawings.

Referring now to the drawings, particularly to FIG. 1, it will be seen that the 'impack crusher of the present invention comprises an exterior casing generally desig nated 1 having disposed within the lower area thereof a rotor 2 mounted upon a rotor shaft 3, which is journaled by any suitable and conventional means within the side walls of the casing 1. The general operation of the apparatus will be readily understood by reference to this figure. The material to be disintegrated is delivered through the feed opening 4 where it is directed with the assistance of the depending chains 5 over the inclined chute 6 in a radial direction towards the rotating hammer 7 fixedly attached to the rotor 2. The feed of the material is directed to the rotor 2 at a point approximately 40 ahead of the top of the hammer swing. The result-ant impact on the rock causes it to break down into smaller particles which are projected largely upwardly against a complement of rigid square primary breaker bars 8 and 9 fixedly attached to the top walls of the casing 1. Considering that the primary crushing occurs upon the initial impact of the hammers 7 upon the feed material, it will be understood that maximum secondary crushing occurs when the resulting broken product drops back after impact with the breaker bars 8 and 9 into the rotor area to receive another impact prior to being projected further towards the discharge area 10 of the crushing chamber. Before proceeding to the lower portion of the discharge area 10, the particles are impacted against a vertical curtain of spaced horizontal round breaker bars 11. These bars may be referred to as the secondary breaker bars, Disposed closest to the periphery of the rotor 2 is an adjustably and yieldably mounted breaker bar 12. Any material not passing between the spaced apart horizontal breaker bars 11 into the discharge area 10 but which is directed back towards the rotating hammers 7 and progresses downwardly toward the yieldable breaker bar 12 receives a final or tertiary crushing as the particles are nipped and pulled through to the lowest portion of the discharge area.

Improved means are shown permitting the ready replacement and/or relocation of the breaker bars 11. The end wall of the casing 1 includes a breaker bar housing 13 which is hingedly connected as at 14 adjacent the bottom corner thereof to permit tilting of the housing 13 from the full line position to the dotted line position as shown in FIG. 1

The pivital movement of said housing is readily achieved by actuation of a power cylinder 15 anchored at one end 16 with respect to the casing 1 and having its opposite end pivotally connected to the housing 13 as at 17. Preferably, one of these cylinders is provided at each side of the apparatus. The horizontal breaker bars 11 are supported by suitable bearings (not shown) mounted in a pair of primary journal plates 18 removably attached by any suitable means to the side walls of the breaker bar housing 13. A smaller secondary journal plate 19 removably attached to each of the side walls of the casing 1 completes the supporting means for the horizontal breaker barsll. From the foregoing, it will be seen that when it is desired to service the bars 11 it is merely necessary to actuate the power cylinders 15 to move the housing 13 away from the casing 1 to its tilted position. In this position the bars may be readily inspected and serviccd and should it be necessary to remove the bars from the housing, this may be accomplished by any suitable overhead hoist means whereupon the bars may be lifted upwardly in a straight line direction with a minimum amount of down-time loss. If it is desired to alter the spacing of the horizontal breaker bars 11 in order to vary the final size of the end product as discharged through the area 10, this is achieved by first lifting out all of the breaker bars 11 from the opened housing 13 and then by removing both the primary journal plates 18 and the secondary journal plates 19 from both sides of the housing 13 and easing 1, respectively, and replacing the removed journal plates with other journal plates provided with bearing surfaces disposed with different spacings therebetween whereupon the breaker bars 11 are there after dropped back into position and the housing 13 returned to its closed position where it is secured by any suitable locking means such as the key lock 20. It will be understood that other changes in the breaker bar arrangement can be accomplished such as shape of bar, vertical rather than horizontal mounting, etc.

The details of the hammer-rotor construction are illustrated most clearly in FIGS. 2-5. In the present embodiment, a pair of hammers 77 are shown disposed in diametrically opposed relationship within the periphcry of the rotor 2. Each of the hammers 7 is adapted to be rigidly attached to a rotor abutment face 23 by means of a plurality of bolts 24 and includes safety lock means in the nature of a pair of wedge blocks 2525 held in locking position by means of a draw bolt 26. As will be most clearly seen in FIG. 3, each hammer 7 is disposed within a transverse groove 27 formed in the periphery of the rotor 2. The area of the groove 27 extends beyond the substantially radial abutment face 23 of the rotor and is joined thereto by an undercut face 28 on the rotor, which face 28 is disposed substantially perpendicular to the radius of the rotor 2. The rear of the hammer 7 is provided with an outwardly facing shoulder 29 which, when the rear mounting surface 7a of 'the hammer is mounted juxtaposed the abutment face 23 of the rotor, will engage the undercut face 28 as shown in FIG. 3. During limited service, the aforedescribed attaching bolts 24 would suffice to retain the hammer 7 in their mounted position upon the rotor 2. However, in view of the extreme forces generated durirlg impact of the material being crushed with the hammer 7 together with the normal centrifugal force imparted to the hammers as well as the inherent abrasive action of the crushed material, the bolts 24 are subjected to damaging forces quite often causing their complete failure.

Accordingly, positive means are included for insuring the retention of the hammers 7 against the rotor abutment face 23 and undercut face 28, even should all of the bolts 24 become broken during the operation of the apparatus. As will be seen most clearly in FIG. 5, the bottom of the hammer 7 is provided with a plurality of eyes 30, each provided with aligned longitudinal bores 31. Each end of the hammer includes, on its bottom surface, an inclined wedge face 32 having a longitudinal cutout 33 in alignment with the bores 31. Disposed between the two hammer eyes 30-30 as well as between each inclined wedge face 32 and its adjacent hammer eye, is a recess 34 the purpose of which will become apparent immediately hereinafter. The disposition of the fiat inclined Wedge face 32 at either end of the hammer 7 is quite important. As will be seen in FIG. 3, a line perpendicular to the transverse plane of the wedge face 32 and passing through the center of the draw bolt 26, if extended, intersects the mating surfaces of the outwardly facing shoulder 29 of the hammer and undercut face 28 of the rotor.

Projecting outwardly from the base of the transverse groove 27 in the rotor are a plurality of eyes 34a provided with transverse apertures 35. As will be seen in FIG. 2, the hammer 7 is disposed within the groove 27 with the hammer eyes 30-30 and wedge faces 32-32 straddling the rotor eyes 34a. Following the application of the bolts 24, the draw bolt 26 is passed through the longitudinally aligned apertures 35 and bores 31 whereafter a wedge block 25 is slipped upon each end of the bolt 26. The construction of the wedge block 25 will be apparent from FIG. 4 wherein it will be seen that the block is formed from cylindrical stock and includes a flat inclined wedge surface 36 extending from the outer end 37 of the block at a point above the longitudinal bore 38 to a point at the inner end 39 of the block bisecting the bore 36. When the wedge blocks 25 are disposed about the bolt 26 and the nuts 40 are tightened, it will be seen that the flat inclined wedge surface 36 of the wedge blocks 25 will abut the inclined wedge face 32 formed on the hammer 7 and all forces generated as the nuts 40 are tightened will be transmitted by the in-. wardly moving wedge blocks as a force resultant in the direction of the dotted line extending from the center of draw bolt 26 to the undercut surface 28 in FIG. 3, tending to urge the key section 41 of the hammer towards the juncture of the undercut face 28 of the rotor and the adjacent side wall of the groove 27. From the foregoing, it will be understood that even though all of the bolts 24 should become broken during operation of the apparatus, the locking force obtained as a result of the wedge blocks 25 and nuts 40 of the draw bolt 26 will securely retain the hammers in their fixed relationship within the periphery of the rotor.

The support means for the previously mentioned yieldable breaker bar 12, which cooperates with the rotating hammers 7-7 to provide a final or tertiary crushing zone, is illustrated in detail in FIGS. 6 and 7. The releasable support assembly shown in these figures is mounted upon the two opposite side walls 1a of the casing 1, and each includes, a pair of journal blocks 4343 having opposed arcuate bearing surfaces 12a-12a for engaging the opposite free ends of yieldable breaker bar 12. When initially determining the spacing in the tertiary crushing zone, the journal blocks 43 are positioned the desired distance from the rotating hammers to achieve the selected final product size of the crushed material in this zone. After positioning the journal blocks 43 between the top plate 44 and bottom plate 45, a suitable number of shims 46 are placed in front of and behind each of the journal blocks as shown most clearly in FIG. 7. A sufiicient number of shims 46 are placed to the rear of the journal blocks 43 to take up all slack between the journal blocks and a back-up plate 47 extending between the top plate 44 and the bottom plate 45. A shear bar 48 is suitably attached, such as by welding, to the rear face of the back-up plate 47 and is provided on its other free end with an axial tapped opening 49. A shear plate 50 is adapted to be mounted at the free end of the shear bar 48 by means of the mounting collar 51 and retainer 52, between which the shear plate 50 is disposed and retained by means of a threaded bolt 53 passing through the assembled elements and into the tapped opening 49. A cylindrical relief tube 54 having its outer end in abutment with a stop plate 55 is further supported in a suspended position by means of a plurality of reinforcing struts 56 so that the forward open end 57 thereof will be axially aligned with the shear bar 48. In the thus assembled position, it will be seen that the retainer 52 and mounting collar 51 must of necessity be of a lesser outer diameter than the internal diameter of the relief tube 54 while the fiat shear plate 50 is of a suflicient diameter to at least extend in overlying relationship upon the entire forward end 57 of the relief tube 54. The forward portion of the yieldable breaker bar support assembly includes a base plate 58 through which is threaded an adjustable take-up screw 59. When the journal blocks 43 have been properly positioned and a suitable number of shims 46 placed before and after the journal blocks, the final slack is taken up by advancing the take-up screw 59 rearwardly against the forwardmost shim 46 and the screw 59 retained in this position by a suitable stop-nut 60.

From the above description, the operation of the yieldable breaker bar support assembly should be readily understood. Should a piece of tramp metal or other material too hard to be broken up in the tertiary crushing zone become lodged between the rotor and yieldable breaker bar 12, the force of such material as it is nipped within this area will drive the breaker bar 12 rearwardly, which force will be transmitted through the back-up plate 47, shear bar 48, and mounting collar 51, to the shear plate 50. It will thus follow that should the force exceed the shear rating of the particular shear plate 50 straddling the forward opening of the tube 54, then the mounting collar 51 and tube 54 will actually punch out the center of the shear plate 50 and the movable components will be driven rearwardly through the interior of the relief tube 54, thus precluding damage to the apparatus which might otherwise occur should a nonbreakable substance be caught between the breaker bar 12 and rotating hammers 7.

I claim:

1. A rotary impact crusher, comprising, a casing providing a crushing chamber and having a rotor mounted therein, a plurality of removable hammers attached to the periphery of said rotor, a plurality of primary breaker bars mounted in the top of said chamber, a pivotal housing at one end of said casing containing a plurality of vertically aligned secondary breaker bars, journal means in said housing supporting said secondary bars in spaced apart relationship, means operable to open said pivotal housing to expose said secondary bars from the top of said casing, and an adjustably mounted breaker bar disposed below said secondary bars and including yieldable support means breakable upon the application of a predetermined force to permit radial displacement of said adjustable bar.

2. A rotary impact crusher, comprising, a casing having a rotor mounted therein, a plurality of primary breaker bars fixedly disposed within said casing, a curtain of secondary breaker bars mounted with a pivotal housing at one end of said casing, journal plates disposed in opposite sides of said casing supporting said secondary bars in vertical alignment when said housing is closed, and means operable to pivotally open said housing to displace said secondary bars and expose them from the top of said casing.

3. A rotary impact crusher, comprising, a casing providing a crushing chamber and having a rotor mounted therein, a plurality of removable hammers attached to the periphery of said rotor, said rotor provided with a transverse groove in the periphery thereof for each of said hammers, a plurality of apertured eye members projecting outwardly from within said rotor grooves, an undercut surface on said rotor facing the bottom of each said groove and adjoining a substantially radial abutment surface, said hammers including a plurality of depending apertured eyes disposed between said rotor eye members, a key section on said hammers having an outwardly facing shoulder adapted to engage said rotor undercut surface, and wedge means insertable between said key sections and the bottom of said grooves to retain said hammers within said rotor.

4. A rotary impact crusher according to claim 2, wherein, said journal plates include a pair of primary plates disposed within said housing of said casing and a pair of secondary plates within the side walls of said casing, said primary and secondary plates in mating juxtaposed relationship when said housing is closed, and said housing pivotally connected at its bottom to said casing.

5. A rotary impact crusher according to claim 1, wherein, said journal means includes a pair of primary plates disposed within said housing of said casing and a pair of secondary plates within the side walls of said casing, said primary and secondary plates in mating juxtaposed relationship when said housing is closed, and said housing pivotally connected at its bottom to said casmg.

6. A rotary impact crusher according to claim 3, wherein, said hammers each includes at the opposite ends thereof an inclined wedge face, and said wedge means including a wedge block having an inclined surface mating with said wedge face.

7. A rotary impact crusher according to claim 7, including a draw bolt disposed through said wedge blocks, rotor eye members and hammer eyes and pro-- vided with nuts at the ends thereof axially compressing each pair of said blocks towards one another, whereby, the resultant line of wedging force is directed radially from the center of said draw bolt, bisects said wedge block inclined surfaces and intersects said undercut surface on said rotor.

8. A rotary impact crusher according to claim 1, wherein, said yieldable support means includes, a pair of adjustable journal blocks supporting said adjustably mounted bar, a back-up plate displaceable by movement of said journal blocks, a shear bar having a shear plate attached thereto mounted upon said back-up plate, and a fixed relief tube having one end in abutment with said shear plate.

References Cited UNITED STATES PATENTS Smith 241--194 Wilson 241-194 Kessler 241187 8/1965 Nixon 241-186 9/1928 Roebke 241193 FOREIGN PATENTS 7/1943 Great Britain. 9/ 1952 Great Britain. 8/1952 Great Britain. 2/ 1958 Great Britain.

ROBERT c. RIORDON, Primary Examiner JAMES F. McKEOWN, Assistant Examiner U.S. C1. X.R.

Hanse 241 1s7 15 241 191, 195 

